The present invention relates generally to a display apparatus for a vehicle. More particularly, the invention relates to a display apparatus comprising a filter for restricting a visual range of images displayed on the screen of a CRT with respect to a driver in response to ambient light levels and vehicular running.
In the previously proposed image displaying apparatus, a louver type filter is disposed in front of a CRT so that a visible angle is limited to directions excluding a particular direction in order to prevent the images displayed on the screen of a CRT from being viewed from a vehicular driver's seat during vehicle operation in order to assure driving safety.
While the vehicle is moving, a louver type filter is mounted by a viewer in front of the CRT so that louvers in the filter cause light directed to the driver's seat to be interrupted. The filter however allows the images of the CRT to be projected to the passenger's seat.
When the vehicle stops and parks, the images on the CRT can be viewed from all vehicular seats including the driver's seat.
Another image displaying apparatus has been proposed which includes a liquid crystal panel for controlling a visual angle in place of the louver type filter due to the inconvenience of mounting on and removing it from the CRT. For example, Japanese Utility Model First Publication (jikkaisho) No. 64-28066 exemplifies such a conventional display apparatus.
In this apparatus, controlling means is provided. The controlling means operates to apply a voltage to the liquid crystal panel during running of the vehicle to interrupt the light from the CRT toward the driver's seat and applies no voltage to it when stopped, therefore the images from the CRT can be transmitted in all directions.
However, the transmission factor ratio of such filters is relatively small. The images displayed on the screen of the CRT are visible through the liquid crystal panel during night driving. This gives the driver some distraction.